Spectral estimation from subbands
- 2 January 2003
- conference paper
- Published by Institute of Electrical and Electronics Engineers (IEEE)
Abstract
The results of previous work by the authors (see Conf. on Inform. Sci. and Syst., 1992) are used to prove that subband differential pulse-code modulation (DPCM) provides a coding gain over full-band DPCM for finite orders of prediction. The equivalence of linear prediction and autoregressive (AR) modeling equations are used to estimate source spectra from subbands. Subband decomposition of a source results in a whitening of the composite subband spectrum. This implies that for any stationary source, a p/sup th/-order prediction error filter (PEF) can be found that is better than the p/sup th/ PEF obtained by solving the Yule-Walker equations resulting from full-band data. The existence of such a superoptimal PEF is demonstrated, and a method to optimally allocate a prediction order p/sub m/ to the m/sup th/ subband such that the sum of the p/sub m/'s from m=1 to M equals p, where p is the full-band order of prediction and M is the number of subbands, is proposed.<>Keywords
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